Mechanical hand



Dec. 5, 1950 T. B. SANSBURY MECHANICAL HAND Filed Feb. 6, 1948 I HNN uVII/lllllllllfllfla INVENTOR. THOMAS B. 5/7/V55URY Patented Dec. 5, 1950UNI-TED STAT es TEN-T OFFICE Thisinvention relates 1 to prostheticapparatus and l'1a's1specialv reference-to. an artificial hand.

One important object: of thi's invention is. to provide a novelconstruction. of artificial hand;

Another important. object of this invention is to; provide an artificialhandhaving two claws or: fingers especiallydesigned in a-novel mannerto; ensure. a firm grip on any article grasped'by thehand.

A. further object. of this invention is toprovide a. novel hook-likeartificial hand wherein the fingers will positively lock an objectwithout the necessity of manipulating a locking mechanism by the otherhand;

Still another object of the invention is to provide a novel constructionofartificial hand wherenotratchetor other like lock exists and wherein asingle control wire is all that; is used for opening the fingers.

Yet another object of the invention is to provide anovel shape of clawor finger so formed as to. facilitate the gripping of'an automobile gearshiit,.the graspingof a steering wheel and steering: with it, theopenings ofdoors; and securely holding table utensils, screw drivers,hand saws and many other articles.

With the above and other objects in view, as will bepresently" apparent;the invention con;- sits ingeneral or certain novel details ofconstruction and combinations of parts hereinafter fully described,illustrated in the accompanying drawings, and particularly claimed.

In the drawings, like characters of reference indicate like parts in theseveral views, and

Figure 1 is a plan view of the device with one of the casing coversremoved;

Figure 2 is a view from the right side of Figure 1, the view beingpartly in section;

Figure 3 is a detail section on the line 3-3 of Figure 1;

' Figure 4 is a detail section on the line 4-4 of Figure 1;

Figure 5 is a view partly in elevation and partly in section and showingthe manner of attaching the hand to an arm socket;

Figure 6 is a view partly in elevation and partly in section and showingthe manner of immovably securing one of the fingers; and

Figure 7 is a view from the top of Figure l but showing only certainportions of the fingers.

In the construction of the invention as here shown, there is provided abody In of general U-shape and from the base of the U there extends athreaded lug II for attaching the device to a socket adapted to befitted on the stump of an amputated arm.

On each side of this body I!) is a plate l2 having a centrally disposedH-shaped opening l3, the opening extending transversely of the body andthus having its wider portions adjacent the arms ie-Claims; (01.. 3-12)of the-U. For the pul'noseof describing therelae tive positions. andshapes of certain of' the partsof this device, the axis of the member 5I=is-to be considered as the' central axis of the hand; To avoidconfusion, the parts, to the right. and. le-ft of Figure 1 will be soreferred to, while those parts extending back: from Figure 1 wilt becon.- sidered as extending or located rearwardly of this imaginary axis.I

On the right leg of the. body. Ii! a; rabbet I4 is formed. At i5 is afixed arm, this arm having, a rabbet 56 which overlaps with and. fitsin. the rabbet M; A screw ll passes through the over-- lapping, portionsof therabbets and firmly con.- nects them. A bolt It also connects; thefront plate 12' with, the arm l5 sovthatthe armis-held rigid againstmovement in any direction.

Extending between the arms of the U-shapedbody It is a shaft l9; On thisshaft is rotatably mounted an operating member having a; drum 20 at oneend and acylindrical opposite. end 21. Between the ends 26 and 21. theoper ating member is formed as a deeply grooved.-screw- 22.. Extendingbetween the plates [2 isv a pivot. bolt 23 whereon is pivoted. amovablearm.- 24. This arm 24 has a nose 25. which engages in the: grooveof the screw 22 so that rotation of this screw effects biasing movementof the arm 2'42, The. arms I5. and 24' are reversely curved. so:

as to present arcuate bends 26 with their concave I sides confrontingand with the outer ends of these bends substantially in contact. Theterminal portions of the arms 15 and 24 are bent rearwardly to formfingers 21, as best seen in Figure 2. The fingers 2! have arcuate bends28, the concave sides of which are in opposition, thus enabling anythinggripped by the fingers to be securely held. Around the drum 20 is wounda cord of cable 29 which passes through a suitable opening in the baseof the body and carries on its free end a connector 30 for the operatinwire (not shown). When tension is exerted on this cable, the screw 22 isrotated. Fixed to and wound spirally about the end 2| is a spring 3|which extends along the rear plate I2 and has its end secured thereto bya screw 32. The spring 3| constantly tends to rotate the screw 22 insuch direction that the nose 25 moves to the left and the arm 24 thustends to close on the arm I5. The cable 29, when sufficient tension isbrought thereon, will rotate the screw 22 in the opposite directionagainst the action of said spring and thus cause movement of the movablearm 24 away from the fixed arm l5 as indicated by the broken lines inFigure l. I

In Figure 5 there is shown a sleeve 33 for covering the stump of anamputated arm and provided with a metallic cuff end 34 through which thescrew II I projects and is there secured as shown at 35.

Covering caps 36 are secured to the plates [2 to protect the operatingmechanism and to render the device attractive in appearance.

What is claimed is:

1. In an artificial hand, a body, an articlegripping arm immovably fixedto said body, a second arm pivotally mounted intermediate its ends onsaid body and movable toward and from the fixed arm, said second armhaving an outwardly extending article-gripping portion and a secondportion extending inwardly of said body, an operating screw extendingtransversely of said body, a nose on the second portion of said secondarm directly engaging said screw, said screw being elongated and of lessdiameter in its center than at its ends and presenting a concavelyarcuate pitch surface, and means to rotate said screw in each direction.

2. In an artificial hand, a body, an articlegripping arm immovably fixedto said body, a second arm pivtotally mounted intermediate its ends onsaid body and movable toward and from the fixed arm, said second armhaving an outwardly extending article-gripping portion and a secondportion extending inwardly of said body, an operating screw extendingtransversely of said body, a nose on the second portion of said secondarm directly engaging said screw, said screw being elongated and of lessdiameter in its center than at its ends and presenting a concavelyarcuate pitch surface, an operating cord arranged to rotate the screw inone direction, and a sprnig urging the screw in the opposite direction.

3. In an artificial hand, a body, an articlegripping arm immovably fixedto said body, a second arm pivotally mounted intermediate its ends onsaid body and movable toward and from the fixed arm, said second armhaving an outwardly extending article-gripping portion and a secondportion extending inwardly of said body, an operating screw extendingtransversely of said body, a nose on the second portion of said secondarm directly engaging said screw, said screw being elongated an of lessdiameter in its center than at its ends and presenting a concavelyarcuate pitch surface, a drum at one end of said screw, a cord woundaround said drum and rotating the drum and screw in one direction uponthe cord being drawn ofi the drum, and spring means urging the drum andscrew in the opposite direction.

4. In an artificial hand, a body, an articlegripping arm immovably fixedto said body, a second arm pivotally mounted intermediate its ends onsaid body and movable toward and from the fixed arm, said second armhaving an outwardly extending article-gripping portion and a secondportion extending inwardly of said body, an operating screw extendingtransversely of said body, a nose on the second portion of said secondarm directly engaging said screw, said screw being elongated and of lessdiameter in its center than at its ends and presenting a concavelyarcuate pitch surface, a drum at one end of said screw, a cord woundaround said drum and rotating the drum and screw in one direction uponthe cord being drawn ofi the drum, a cylinder at the end of the screwremote from the drum, and a spring coiled around said cylinder in adirection opposite the winding of said cable and having one end fixed tosaid body.

THOMAS B. SANSBURY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,046,966 Carnes Dec. 10, 19121,285,617 Caron Nov. 26, 1918 2,409,884 Mollenhour Oct. 22, 1946 OTHERREFERENCES Page 26 of Terminal Research Reports on Artificial Limbs,published by National Research Council and received in Div. November 13,1947.

